AIN based call routing, transfer and conferencing methods and apparatus are disclosed. In various embodiments initial call routing is based on the availability of a party to service a call as determined from a computer system associated with the party selected to service the call. The party's computer system supports a telephone application programming interface (TAPI) which allows a telephone network server to determine the availability of the party selected to service the call from, in part, TAPI obtained telephone line status information. The network server supplies call related data to the computer system of the party assigned to service the call. Call transfer and conferencing operations along with the transfer of call related data are also supported. AIN mid-call triggers are used in some embodiments to support call transfer and conferencing operations.